Cursed Giant Boar

Charge. If the boar moves at least 20 feet straight toward a target and then hits it with a tusk attack on the same turn, the target takes an extra 7 (2d6) slashing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Relentless (Recharges after a Short or Long Rest). If the boar takes 10 damage or less that would reduce it to 0 hit points, it is reduced to 1 hit point instead.

Shadow Blend. While in dim light or darkness, the shadow mastiff can use a bonus action to become invisible, along with anything it is wearing or carrying. The invisibility lasts until the shadow mastiff uses a bonus action to end it or until the shadow mastiff attacks, is in bright light, or is incapacitated.

Sunlight Weakness. While in bright light created by sunlight, the shadow mastiff has disadvantage on attack rolls, ability checks, and saving throws.

Ethereal Awareness. The shadow mastiff can see ethereal creatures and objects.

Tusk. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) slashing damage.